This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Phospholipases catalyze the hydrolysis of membrane phospholipids, which, in turn, generates a variety of lipid second messengers. These lipid-derived products are necessary for both physiological and pathological processes. An understanding of phospholipid metabolism, as it relates to cancer, is necessary for diagnostic applications and for developing novel targeted chemotherapy. Traditionally, lipid metabolite changes have been observed by magnetic resonance spectroscopy (MRS) or by chromatographic methods. Using a combination of MRS with near-infrared (NIR) fluorescent molecular probes we are targeting phospholipase function with the goal of delineating specific cell signaling pathways in vivo. The information gained from a molecular imaging approach may lead to earlier diagnoses and improved management of disease.